Session 6 - HII Regions & Massive Star Formation.
Display session, Wednesday, January 07
Exhibit Hall,

## [6.04] Extinction and Dust Associated with the Compact HII Region S88B

J. A. Goetz, J. L. Pipher, W. J. Forrest (U. Rochester)

We present high spatial resolution infrared images of the inner arcminute of the compact HII region S88B (G61.5+0.1) in Br \alpha (4.052 \mum) and Br \gamma (2.167 \mum) lines, and in the polycyclic aromatic hydrocarbon features at 3.3 and 3.4 \mum. We examine a more extensive region (2\arcmin by 2\arcmin) in broad band images at J (1.25 \mum), H (1.65 \mum) and K (2.23 \mum). The observations were performed at the Mt. Lemmon Observing Facility 1.5 m telescope with the University of Rochester Third Generation Infrared Camera. Assuming the Brackett line emission to be optically thin, a 10% number abundance of He (all HeII), and a power-law fit to the extinction (\tau_\lambda \propto \lambda^-\alpha, \alpha = 1.5 [Howard, et al. 1996]), we are able to map the extinction implied by our Br \alpha and Br \gamma emission images. We propose the 3.3 and 3.4 \mum emission outlines the PDR around the inner region of Brackett line emission.